• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.82-91
• /
• 2020

Recently, the research and development of weapon systems have expanded from ILS centered on acquisition costs to LCS, including operating maintenance costs. Regulations define the provision and formula of operating maintenance costs, but this does not consider the characteristics of the design and operation/maintenance of real weapon systems based on engineering calculations. Therefore, this study suggests a simulation design method to complement these areas and produce more accurate operating maintenance costs. The research procedures are as follows. First, the provision and formula of operating maintenance costs were defined to make the simulation results applicable. Second, a simulation model was developed by reviewing design considerations so that the simulation results reflect reality more accurately. The design considerations include the PBS of weapon systems, operation schedules, specifications for operation/maintenance/warehouse facilities, and basic cost information (personnel expense and spare part/equipment cost). This study is expected to be effective in calculating the operating maintenance costs more easily and accurately.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.20 no.4
• /
• pp.126-131
• /
• 2012

In South Korea, there is no consideration for increasing labor costs and price fluctuation regarding the commission for a flight inspection. Because this causes a deficit in the flight inspection related operation, the cost system should be improved. Therefore, this research considers the first cost analysis in order to calculate a proper flight inspection commission through three different types of cost making methods. Moreover, as flight inspections are held by flights and human labors, labor costs are included as the main operation cost. According to the research, it is analyzed that the total cost to process flight inspection operations is decided by the scope of aircraft operation.

• Proceedings of the KIEE Conference
• /
• 1997.07c
• /
• pp.797-799
• /
• 1997

This paper presents an operation and planning model of integrated energy systems which consist of small scale cogeneration systems, thermal accumulator, ice storage and electrical energy storage systems. In the proposed planning model, an optimization of total cost which contains investment, operation, thermal shortage and salvage costs has carried out with the maximum principle based on the lifetime of each system component and unit price per capacity. From this model, optimal investment capacity per annum can be determined during the studied periods using the marginal costs according to the operation characteristics of each system component.

• KIEE International Transactions on Power Engineering
• /
• v.11A no.4
• /
• pp.39-44
• /
• 2001

As electric power systems have been moving from vertically integrated utilities to a deregulated environment, the charging of reactive power management is a new challenging them for market operators. This paper proposes a new methodology to compute the costs of providing reactive power management service in a competitive electrical power market. The proposed formulation, which is basically different from those shown in the literature, consists of two parts. One is to recover investment capital costs of reactive power supporting equipment based on a reactive power flow tracing algorithm. The other is to recover operational costs based on variable spot prices using the optimal power flow algorithm. The charging shapes resulted from the proposed approach exhibit a quite good meaning viewed from a practical sense. It turns out that reactive power charged are mostly due to recovery of capital costs and slightly due to recovery of operational costs. The methods can be useful in providing additional insight into power system operation and can be used to determined tariffs of a reactive power management service.

• Proceedings of the KIEE Conference
• /
• 2001.11b
• /
• pp.77-82
• /
• 2001

As electric power systems have been moving from vertically integrated utilities to a deregulated environment, the charging of reactive power management is a new challenging theme for market operators. This paper proposes a new methodology to compute the costs of providing reactive power management service in a competitive electrical power market. The proposed formulation, which is basically different from those shown in the literature, consists of two parts. One is to recover investment capital costs of reactive power supporting equipment based on a reactive power flow tracing algorithm. The other is to recover operational costs based on variable spot prices using the optimal power flow algorithm. The charging shapes resulted from the proposed approach exhibit a quite good meaning viewed from a practical sense. It turns out that reactive power charges are mostly due to recovery of capital costs and slightly due to recovery of operational costs. The method can be useful in providing additional insight into power system operation and can be used to determine tariffs of a reactive power management service.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.32 no.4
• /
• pp.45-52
• /
• 2009

The objective of this was to improve a transportation cost relation between Central Distribution Centers(CDCs) and Regional Distribution Centers(RDCs), to control inventory cost concerning safety stock for each service level, by reviewing distribution steps connecting CDCs and RDCs under the price discount. It was also to examine and compare operating costs for the following two alternative suggestions for setting the service standard as a counter measure for a stock-out of the distribution network system management. First, provision by dispersing the safety stock to the CDCs and RDCs; and second, exclusive provision of the safety stock only to the RDCs. The cost comparison analysis was made for each category of purchase costs, regular transportation costs, express transportation costs, and inventory holding costs.

• Journal of Korean Institute of Industrial Engineers
• /
• v.21 no.3
• /
• pp.329-343
• /
• 1995

Traditionally, machining process sequence was influenced and constrained by the design information obtained from CAD data base, i.e., class of operations, geometric shape, tooling, geometric tolerance, etc. However, even though all the constraints from design information are considered, there may exist more than one way to feasibly machine parts. This research is focused on the integrated problem of operations sequencing and machine tools selection in the presence of the product mix and their production volumes. With the transitional costs among machining operations, the operation sequencing problem can be formulated as a well-known Traveling Salesman Problem (TSP). The transitional cost between two operations is expressed as the sum of total machining time of the parts on a machine for the first operation and transportation time of the parts from the first machine to a machine for the second operation. Therefore, the operation sequencing problem formulated as TSP cannot be solved without transitional costs for all operation pairs. When solved separately or serially, their mutual optima cannot be guaranteed. Machining operations sequencing and machine tool selection problems are two core problems in process planning for discretely machined parts. In this paper, the interrelated two problems are integrated and analyzed, zero-one integer programming model for the integrated problem is formulated, and the solution methods are developed using a Tabu Search technique.

• Journal of Distribution Science
• /
• v.20 no.9
• /
• pp.11-21
• /
• 2022

Purpose: Many concerns have appeared in banking sector in the digital era and one of them is that technology development will increase operation costs of banks. Motivated by this issue, our study aims to explore the effect of technological and digital investments on cost-effectiveness of banking operation. Research design, data and methodology: To reach a clear answer, we use the data of 12 commercial banks spanning from 2011 to 2020 in Vietnam and employ multivariate regression analysis as well as perform various robustness tests. Results: Our regression result indicates that the adverse effect of technological spending on cost-effective operation. This finding still remains unchanged when we conduct different robust tests. Also, we find that this negative impact becomes more evident in large banks than in small ones. Conclusions: The paper provides one of the most important empirical results for mangers and policy-makers in banking sphere, especially in Vietnam where regulators have been calling for continuously investing into technological innovation in banks. The evidence confirms that banks should carefully consider an increase in spending on distribution information and communication technologies when constructing business strategies related to expanding digitalization. Our research is also useful for countries having similar financial structure to Vietnam.

• Korea Journal of Hospital Management
• /
• v.10 no.3
• /
• pp.45-66
• /
• 2005

The purpose of this study was to analyze related factors affecting profitability on general hospitals(300-499 beds). The data were derived from survey by the Korean Hospital Association on 33 hospitals during 10 years (from 1993 to 2002). Profitability was measured by 3 ratios - net profit to total assets, normal profit to total assets and operating margin to gross revenue - as dependent variables. Independent variables were classified by general factors (ownership, number of bed, period of establishment, region), financial factors (total asset turnover, current ratio, liabilities to total assets, personnel costs per operation profit, material costs per operation profits), productivity index(number of daily patient per nurse), the score of quality assurance activity and the time lag score. Multiple regression model was used in this study. First, Number of bed, region was not statistically significant for profitability. But ownership was affect positively to normal profit to total assets and operating margin to gross revenue. Private hospitals had higher profitability than that of public hospitals Second, the score of quality assurance activity was not statistically significant to profitability. Third, Those hospitals having more daily patient per nurse had significantly higher profitability than the others. Fourth, Those hospitals having higher proportion in total asset turnover had significantly higher profitability than other hospitals. But liabilities to total assets and liquidity ratio had no difference to the profitability. Those hospitals having higher proportion in personnel costs and material costs per operation profits had significantly lower hospital profitability than others.

• Journal of Korean Society of Transportation
• /
• v.31 no.2
• /
• pp.80-89
• /
• 2013

The purpose of this research is to optimize the line planning of the intercity passenger railway. In this study, the line planning problem has been formulated into a mixed integer programming by minimizing both user costs (passenger's total travel time) and operator costs (operation, maintenance and vehicle costs) with multiple train types. As a solution algorithm, the branch-and-bound method is used to solve this problem. The change of travel demand, train speed and the number of schedules have been tested through sensitivity analysis. The optimal stop-schedules and frequency as well as system split with respect to each train type have been found in the case study of Kyoung-bu railway line in Korea. The model and results of this research are useful to make a decision for railway operation strategy, to analyze the efficiency of new railway systems and to evaluate the social costs of users and operators.